Abstract

3D Printing for Engineering Complex Tissues

John Fisher, Professor and Associate Chair, University of Maryland

The generation of complex tissues has been an increasing focus in tissue
engineering and regenerative medicine. With recent advances in
bioprinting technology, our laboratory has focused on the development of
platforms for the treatment and understanding of clinically relevant
problems ranging from congenital heart disease to preeclampsia. We
utilize stereolithography-based and extrusion-based additive
manufacturing to generate patient-specific vascular grafts, prevascular
networks for bone tissue engineering, dermal dressings, cell-laden
models of preeclampsia, and bioreactors for expansion of stem cells.
Furthermore, we have developed a range of UV crosslinkable materials to
provide clinically relevant 3D printed biomaterials with tunable
mechanical properties. Such developments demonstrate the ability to
generate biocompatible materials and fabricated diverse structures from
natural and synthetic biomaterials. In addition, one of the key
challenges associated with the development of large tissues is providing
adequate nutrient and waste exchange. By combining printing and
dynamic culture strategies, we have developed new methods for generating
macrovasculature that will provide adequate nutrient exchange in large
engineered tissues. Finally, the use of stem cells in regenerative
medicine is limited by the challenge in obtaining sufficient cell
numbers while maintaining self-renewal capacity. Our efforts in
developing 3D-printed bioreactors that mimic the bone marrow niche
microenvironment have enabled successful expansion of mesenchymal stem
cells by recapitulating the physiological surface shear stresses
experienced by the cells. This presentation will cover the diverse
range of materials and processes developed in our laboratory and their
application to relevant, emerging problems in tissue engineering.